The effect of video-feedback on the learning of the tennis service by intermediate players     

P C Van Wieringen  H H Emmen  R J Bootsma  M Hoogesteger  H T Whiting 《Journal of sports sciences》1989,7(2):153-162

Effects of video-feedback on improvement of the tennis service were investigated in subjects having at least 2 years of playing experience in tennis. The experiment was carried out in an indoor tennis hall under normal training conditions. Subjects were randomly divided into three groups: a video-feedback training (VFT) group, a traditional training (TT) group and a control group, each consisting of 22 subjects. While the subjects of the control group received no training at all, subjects in both the VFT and TT groups were trained twice weekly during 5 consecutive weeks. Each training session lasted 40 min, of which 30 min was spent on actual practice in training of the service. The remaining 10 min was spent on watching, analysing and discussing video recordings of either their own service performed during the training session (VFT group), or ground strokes and volleys of top level players (TT group). Both the VFT and TT group showed significantly greater improvements in both achievement scores and form (technique) scores than did the control group. No differences, however, could be demonstrated between the VFT and TT group, indicating that the subjects of the former group did not benefit from the video-feedback they received. While form scores correlated significantly (P less than 0.001) with the velocity of the served ball, no such relation between form scores and spatial accuracy was apparent.  相似文献   

Dust showers     

Washington Jones  W Barnet Le Van  Tinius Olsen  William M Henderson  Wm.D Marks 《Journal of The Franklin Institute》1880,110(2):106-114

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The weakening of steam boilers by cutting holes in the shell for domes and necks     

W. Barnet Le Van 《Journal of The Franklin Institute》1880,110(5):313-323

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Refining the ethics of computer-made decisions: a classification of moral mediation by ubiquitous machines     

Marlies Van de Voort  Wolter Pieters  Luca Consoli 《Ethics and Information Technology》2015,17(1):41-56

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Building Your Licensing and Negotiation Skills Toolkit     

Claire Dygert  Robert Van Rennes 《期刊图书馆员》2015,68(1-4):17-25

Licensing and the negotiating of electronic resources can be a daunting task for librarians who lack the proper skill sets and are unfamiliar with the intricacies of publisher agreements. Claire Dygert broke down the individual elements of a standard licensing agreement and explained the importance of protecting the rights of libraries. By providing insight from her years of experience, librarians learned how to develop a support network, build confidence, and be more effective negotiators.  相似文献   

#MeToo,sexual harassment: an article,a forum,and a dream for the future     

Robin Patric Clair  Nadia E. Brown  Debbie S. Dougherty  Hannah K. Delemeester  Patricia Geist-Martin  William I. Gorden 《Journal of Applied Communication Research》2019,47(2):111-129

#MeToo has breathed new life into the women’s movement and especially into understanding and rectifying sexual harassment, abuse and assault. It has galvanized activists around the globe. And it has placed thousands of stories of the harassed in full view of the public. Sexual harassment, abuse and assault may occur within the organizational context or beyond; but sexual harassment, in particular has been legally labeled an organizational phenomenon. With this in mind, Robin Clair frames the early part of this article around the most recent organizational communication theories (see the appendix for an overview of these theories). Following the essay is a forum, in which invited scholars address questions related to the #MeToo movement.  相似文献   

Priming and Fake News: The Effects of Elite Discourse on Evaluations of News Media     

Emily Van Duyn  Jessica Collier 《Mass Communication and Society》2019,22(1):29-48

Fake news has become a prominent topic of public discussion, particularly among elites. Recent research has explored the prevalence of fake news during the 2016 election cycle and possible effects on electoral outcomes. This scholarship has not yet considered how elite discourse surrounding fake news may influence individual perceptions of real news. Through an experiment, this study explores the effects of elite discourse about fake news on the public’s evaluation of news media. Results show that exposure to elite discourse about fake news leads to lower levels of trust in media and less accurate identification of real news. Therefore, frequent discussion of fake news may affect whether individuals trust news media and the standards with which they evaluate it. This discourse may also prompt the dissemination of false information, particularly when fake news is discussed by elites without context and caution.  相似文献   

Modeling Growth in Electronic Learning Environments Using a Longitudinal Random Item Response Model     

Damazo T. Kadengye  Eva Ceulemans  Wim Van Den Noortgate 《Journal of Experimental Education》2015,83(2):175-202

In educational environments, monitoring persons' progress over time may help teachers to evaluate the effectiveness of their teaching procedures. Electronic learning environments are increasingly being used as part of formal education and resulting datasets can be used to understand and to improve the environment. This study presents longitudinal models based on the item response theory (IRT) for measuring persons' ability within and between study sessions in data from web-based learning environments. Two empirical examples are used to illustrate the presented models. Results show that by incorporating time spent within- and between-study sessions into an IRT model; one is able to track changes in ability of a population of persons or for groups of persons at any time of the learning process.  相似文献   

Estimation of a Nonlinear Intervention Phase Trajectory for Multiple-Baseline Design Data     

Ian Hembry  Rommel Bunuan  John M. Ferron  Wim Van den Noortgate 《Journal of Experimental Education》2015,83(4):514-546

A multilevel logistic model for estimating a nonlinear trajectory in a multiple-baseline design is introduced. The model is applied to data from a real multiple-baseline design study to demonstrate interpretation of relevant parameters. A simple change-in-levels (ΔLevels) model and a model involving a quadratic function (Quadratic) for the nonlinear intervention phase data were also estimated. In addition, a simulation study was conducted to assess Markov chain Monte Carlo estimation of the logistic model and compare its trajectory recovery with use of the ΔLevels and Quadratic models. While most of the logistic model's parameter values were recovered well, trajectory recovery was very reasonable using the simpler Quadratic model. Results are discussed along with recommendations for practitioners and directions for future research.  相似文献   

Endorsing achievement goals exacerbates the big-fish-little-pond effect on academic self-concept     

Sofie Wouters  Hilde Colpin  Jan Van Damme  Karine Verschueren 《教育心理学》2015,35(2):252-270

The big-fish-little-pond effect (BFLPE) model predicts students’ academic self-concept to be negatively predicted by the achievement level of their reference group, controlling for individual achievement. Despite an abundance of empirical evidence supporting the BFLPE, there have been relatively few studies searching for possible moderators. Integrating the BFLPE model with Achievement Goal Theory, the present study aims to determine whether the negative effect of class-average achievement on academic self-concept is moderated by individual and class-average achievement goals. Our sample comprised of 2987 students (50% boys) from Grade 6 in 112 elementary schools in the Flemish region of Belgium (174 classes). Applying multilevel modelling, we found a stronger BFLPE when students’ individual achievement goals were higher, regardless of the specific nature of these goals. The BFLPE was not moderated by class-average levels of achievement goals. Overall, our findings demonstrate that the BFLPE is moderated by individual goal-related factors.  相似文献